Furnace-grate.



No. 824,534. PATBNTED JUNE 26, 1906. E EINFELDT FURNACE GRATE.

APPLICATION FILED MAY 3, 1904.

LSHEB SHEET 1.

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Witness PATENTED JUNE 26, 1906. E. EINPELDT. FURNACE GRATE.

APPLIGATION FILED MAY3 1904 4 SHEETS-SHEET 3.

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No. 824,534. PATENTED JUNE 26, 1906.

E. EINFELDT.

FURNACE CRATE.

APPLICATION FILED MAY 3. 1904.

4 SHEETS-SHEET 4.

Q M S UNITED STATES PATENT OFFICE.

EHIL EINFELDT, OF DAVENPORT, IOWA, ASSIGNOR TO BETTEND ORF METAL WHEELCOMPANY, A CORPORATION OF IOWA. h

FURNACE-GRA'l'E.

provement in. Furnace-Grates, of which the following is a specification.This invention relates to furnace-grates of the ty e wherein thegrate-bars are carried by en less traveling chains, which grates areused for burning fuel in a finely-divided condition; and the inventionconsists in various improvements designed with a view of. ,obtaining themost eflicient consumption of the fuel and gases, the uniform and properfeeding of the fuel, and the effective operation of the mechanismgenerally.

In the accompanying drawin s,Figure 1 is.

a longitudinal section throu a furnace equipped with grates embodying myinvention. Fig. 2 is a vertical transverse sectional elevation on theline a aof Fig. 1. Fig.

3 is a horizontal sectional plan view on the line b b of Fig. 1. Fi 4 isa transverse section on the line 0 c of ig. 1 Fig. 5 is an endelevation, on an enlarged scale, of a section of the carrying-chains anda number of the grate-bars, showin how the latter are detachablyconnected with the links of the chain. Fig. 6 is a top plan viewof aportion of one of the carrying-chains with the gratebars removed. Fi 7is a bottom plan view of one end of one o the grate-bars. Fig. 8 is atop plan view of the same.

Referring to the drawings, 1 represents the furnzice-chamben-inclosed atthe side by side walls 2 and at the rear by rear walls 3, in whichchamber are arranged travelin grates, in the present instance three innum er 4, 5, and 6, extending side by side throu h the front of thechamber between vertica piers or columns 7 and 8, which latter givesupport to the arches of the masonry on which the boiler is mounted.

The traveling grates comprise each a. series of transversely-arrangedgrate-bars 9, supported at their opposite ends on chains 10, whichchains at the front pass over sprocket:

wheels 11 and 12, mounted on horizontal- 14, 15, and 16, arounwhichdrums the chains have a slip or free movement, while theyareSpecification of Letters Patent.

Application filed May 3. 1904:. Serial No- 206.151.

Patented June 26, 1906.

positively driven by the front sprocketwheels, the result of thisarrangement being that the weight of the fuel on the downwardlytravelingpart of the chain of bars will act by gravity topull them in thedirection of travel,

and thus materially aid their feeding movement.

Therotation of the sprocket-wheels to effect the feeding movement of thegrates is accomplished in the present instance by eccentrics 17, drivenin a suitable manner, to which are connected rods 18, jointed. at theirlower ends by removable pins 8 to levers 19 3 which levers are mountedat their inner ends loosely on'the respective shafts 13 and each ofwhich is provided with a driving-pawl 20,

engaging ratchet-Wheels 21 on the shafts, the

arrangement being such that the vibratory .motion given to the levers bythe eccentrics will advance the shafts intermittently and feed thegrates forward step by step.-

'By the removal of the pins 18, which con nect the rods 18 with thelevers 19, the latter maybe operated manually in case it is necessary toeffect quick movements of the grates inde endently of the actuatingmechanism,

the evers being provided with a handle 22.

for this purpose. It will be noted that by the arrangement described theseveral grates are driven independently of each other from a' commonsource of ower, and either may be operated by hand. y the meansdescribed without disturbing the operationof the others bythe commondriving means.

As a result of the construction described,

the fuel stored in' hoppers 23 at the front of the furnaceand dischargedfrom said hoppers onto the front of'the traveling grates is carried bythem slowly and uniformly from the front to the rear of thefurnace-chamber, being subjected to the action of combustion in itsassage therethrough.

he grate-bars areeach formed on its upper side with an activesupporting-surface '31 for the fuel and on its under side with a convexrib or web 32, which latter conforms to .the surface of theguiding-drums, which are 4 concave between their ends, so that inpassing firmly but detachablyconnected together by a through-bolt 38","passin through holes in the link and grate-bar and heldby a nut 39,

applied to the bolt at the under 'side of thelink. By reason of thismanner of connecting the bars with the linksof the. chains theirindividual removal may be expeditiously effected with littletrouble-while the chains are in motion when it is desired-to re place aburned or injured barwith a newone, the bar being under thesecircumstances re.- moved while passing up at the 'fi'ont'of the furnace,at which point the under. sides of the bars are uppermost and exposedand thefastoning nuts readily accessible. The extreme ends of theate-bars beyond the point of connection wit the chains are formed on theunder sides with bearing-surfaces 40,

which slide on and :are supported by the upper edges of guide-platcs 41and 42, extending longitudinally within the furnace-chamher, the spacesbetween the adjacent guidingplates being spanned or bridged over byfixed grates or plates 47 and 48, respectively. There are two sets ofthese guiding-plates, one of which is situated between grates 4 and 5and gives guiding support, respectively, to the adjacent ends of saidgrates;-.while-the other set issituated between grates 5 and 6 and givessupport'to the adjacentends, respectively, of said grates. Theplates ofthe hrst set are supported at their front ends by the column 7, and attheir rear ends they are fastened to'and sustained by the rear-end of ahorizontal bar A, extending rearwardly longitudinally within thefurnace-chamber from the base of the column 7. The plates ofthe secondset are sustained at their forward ends by column 8 and have their rearends secured toand supported by the rear I iinity to the walls, inwhichzcase, the fuel in end of'a horizontal longitudinalbar B, extendinglongitudinally into the furnacechamber at the base of the same fromthebase of column 8. The stationary grate ,47, which spans the spacebetween movable I propose to' interpose between the outer ends of thetwo outer traveling grates 4 and 6 and the side walls of the furnacestationary grates 50 and 51,respectively,- in order to prevent theextreme heat of the Walls from inj u-.

rionsly affecting the ends of the grate-bars, which action would resultif theends of the bars travel in contact with orin close proxa highdegree of combustionwould heat'the bricks of the wall toanintense-degree and burn out the ends of the grate-hers traveltionaryplate.

. wheels at the front, the

ing closely thereto. By the provision. of the two stationary grates 50and 51 this over or intense heating-of the wall is'prevented, so

that the grate-bars are effectively protected from injury;

The stationary grate 50 before'-alluded 1 to, is firmly secured to theside wall of the furnace, as shown in Fig. 2, and it gives support tothe guiding-plate at this point, which guiding-plate is bolted to theside of the sta- In like manner the other sta tionary grate 51 at theopposite side of the" furnace-chamber is firmlysecured to the side wallof the furnace and gives support to the guiding-plate at this point,which latter is bolted to the grate, as in the first instance described.p

- It will beobserved as a result of the construction described andillustrated with respect to the relation of the movable and stationarygrates that the three movable grates are of the usual Width andconjointly, they present a practically continuous extended surface forthe fuel, and the stationary grates are very' narrow in proportion tothe width of the movable grates, their function being to bridge over thenarrow spaces between the movable grates, As a result the fixed gratesin their relations, as described, to the relatively wide travelinggrates serve as a means of bridging over the space between the edges ofthe, traveling grates immediately in rear of the vertical piers 7 and 8,between which the :traveling grates extend at the front.

width of the sationary grates being very The much less than the movablegrates they will offer practically no obstruction to the advance of thebody of fuel as a whole, supported conjointly by all of the grates, sothat the movable grates are enabled to carry a fuel bed of a widthcorresponding to the effect? ive-width of the furnace-chamber and as apracticallv continuous mass.

The re at ve positions of the sprocketquiding-drums at the. rear, andthe guiding-pl chains slide are such that the fuel-supportin bed formedconjoin tly by the grate-bars Wi l'= have a general incl nation downwardfrom the front, and during the greater part of their feeding movementthe vertical space 52 betweenthc front edge of one bar and the rear edgeof the next bar in advance will be contracted. I have found in thepractical operation of the mechanism that if these conditions arepreserved throughout the length of the fuel-bed the formation ofclinkors will recombustion of the same will be interfered with; In orderto overcome these objections, I propose to provide for the furthersepara- I10 ates over which the sult and the fuel will become packed andthe tiori of the bars at a single predeterminedv I point in theirtravel, so as to increase the vertical space between-them at this point,and thus break up the fuel in the processor coking and allow more draftto pass through,

thereby greatly romoting combustion and preventing the ormation ofclinkers. Beyond this point the grate-bars resume their relativepositions and throughout the remainder 01 their travel to theguiding-drums."- I find that the best results are obtained if the barsare opened ,at a point in the furnacechamber about one-third the lengthof the chamber from its front, although of course good results may beobtained if this point of 0 ening is varied within reasonable limits.The openin of the bars at this pointmay be convenient y effected by,having the guiding edges of the plates approach more nearly'thehorizontal, the result being that as the gratebars pass onto theserelatively slo ing ortions or the plates the grate-bars wi l eac betipped upward at its rear edge, and inthis way the space between therear edge of each bar and the rear edge of the next bar behind will bewidened.

On reference to Fig. 1 it will be observed that-the upper edge of theide-plates extends in a straight line at a ownward inclination to thepoint 56, at which point its inclination changes and'extends in a nearlyhorizontal line to the point 55', whence it again extends at a downwardinclination in a straight line for the remainder of its length. As aresult of this construction the grate-bars pursue a straight pathwiththe spaces between them contracted until they arrive at the point 55,,whereupon in passing onto the portion of the plates between the point 55and 56 the spaces between the bars are-suddenly widened, after whichthey pursue a straight path downward to the guiding-drums with thespaces between them again contracted. By this means the combustion ofthe fuel is promoted and greatly aided at a point in the travel of thebed where such increased combustion is most effective At the same timeclinker-s which may have formed arebroken. After passing this point ofgreatest combustion the consumption of the fuel continues active, sothat by the time it arrives at the guiding-drums it. is converted intoashes,

which are discharged, as will be more fully" described hereinafter.

, In order that air may be prevented from passing from beneath thegrates around the rear ends of the same, and thus retard the properdraft through the fuel-bed, I form the rear Wall of the furnaceso thatit will conform closely to the path of the bars as they pass around theguidin -drums, thus forming, in effect, a contracted space 60, havingacurved rear surface 61 and terminatin in a horizontal ledge 62 justbeneath the rums at a point where the bars .begin their return movementsafter passing around the drums. Asthe bars laden with the ashesresulting from the combustion of the fuel pass around the drum they aresuddenly tipped and the 65 ashes are dumped and accumulate in thecontracted space 60, forming a pile on the ledge 62 and banked upagainst the curved surface 61, thus constituting, in effect, a sealwhich closes communication through this space between the under andupper sides of the rates. As the mass of ashes increases in height and 1extends in the path of the bars the latter push them forward and act todirect them into the pit 65, from which they may be conveyed in any,suitable manner. It will be observed, therefore, that by reason of theaccumulatlon of ashes in the contractedspace at the rear of the gratesand, further, by reason of the provision of the imperforate guide-drumsall communication between the under and upper sides of the grates at therear is eifectu: ally closed, so that all the air and draft must passupward through the bed of fuel and hctween the bars, and thus promoteeffective combustion with no retarding effects.

To prevent the undue sagging of the lower part of the chains andgrate-bars, in order to avoid the provisionflof a pit or recess toreceive the sagging part, and to contract as far as possible the spaceoccupied by the grates. I fix beneath the tr veling grates inclinedsupporting-rails 70, hich extend upward from a point just in advance ofthe gliding drums to a point about midway of the length of the chamber,along which rails the bars in their return movements travel and by whichtheyare given direct support and maintained in an elevated position.

Having thus described my invention, what I claim is 1-. In combinationwith a furnace-chainber, traveling grate-bars therein, and means forguiding said grate-bars, first at a downward inclination in a straightline for a porlo 5 tion of their rearward travelfthen at a relativeslope upward with reference to their first movement toward thehorizontal, and finally at a downward inclinationin a straight line forthe remainder of theintravel, substanno tially as described.

2. In combination with a furnace-chamber, traveling grate-bars therein,and means for guiding said bars first at a downward inclination 1n astraight line for about onethird the distance of the length of thegrate, then for a short distance at a relative slope approaching thehorizontal, and upward with reference to their first movement andfinally at a downward inclination in a straight line for the remainderof their rearward travel.

3. In combination with a furnace, an endless chain grate thereincomprising conncct. ed grate bars each formed on its inner side with aconvex longitudinal web or rib, means 1 2 5 for supporting the front ofthe grate, and a ide-drum at the rear over which the gratears pass, saiddrum having its surface conside with ayspace "Bald space being gre caveto receive the ribs of the bars whereby the latter 111 the1r pa sagearound the drum nd effectively guided.

mbination a pill-- arranged side by een adjacent grates, V qly less inwidth than the Width of the individual grates, andsaid are given firmsupp or .4. In a furnace, rallty of traveling g grates-formingccnjointly an extended practically continuous moving fuel-supportingbed, and a narrow stationary grate bridging the spacebetween the movablegrates.

5. In a furnace, the combination with a plurality of movable gratesarranged side by side, of guiding-plates extending longitudinallybetween said movable grates and giving guiding. support to the same, anda stationary grate secured to said guiding-plates and bridging, .thespace between the jinovable rates, said stationary grates being greatlyless in width than the width of the individual as -JI) grates.

6. The combination with a plurality of traveling grates arranged with aspace between them, and adapted to support the bed of fuel and advancethe same as a continuous mass, of a fixed rate situated in the spacebetween the movahle grates and of a-relative Width which, while bridgingthe space between the movable grates will-not afford sufficientresistance to the-movement oi the fuel-bed to interfere with the advanceof the same as a continuous mass; whereby the movable grates are enabledto conjointly support and advance a-iuehbed of great width.

7. In a traveling grate, the combination with'a supporting-chaincomprising a series of jointed links formed with'sockets in'their uppersides and with openings extending downwardly-through thelinks and formincontinuations of the sockets, of a series 0 grate-bars having on theirinner sides depending lu s to enter the sockets in the links,said'grateare and lugs being formed with openings-extending entirelythrou h them in line with the downwardly-exten ing openings in thelinks,and through-bolts extending through said openings in the grate-bars,

whereby the movable grates are enabled to advance, as a continuous mass,a fuel-bed of.

great width.

n testimonywhereof I hereunto set my hand this 25thday of April, 1904,in the pres ence of two attesting witnesses. EMIL EINFELDT.

Witnesses:

J. L. HECHT, A. NEILSON:

